The 33 year-old wing-back arrived from Inter Milan earlier this month.
“Starting this new experience is nice," he told the club's official website. “I have a lot of enthusiasm and desire to do well.
“My new teammates have welcomed me, and the negotiations were quick. I was already talking to Quagliarella.
“I thank him, the coach and the President. I hope to help Fabio score many goals. We all know him, and I want to help Sampdoria.
“Ranieri always had great respect and esteem, many have told me so. We spoke in recent days, I'm here for him. Ferrero was also decisive."
“I think I bring experience, enthusiasm and positivity," Candreva added. “Sampdoria have a great history and don't deserve a similar championship to last season.
“We aim for salvation and we have to keep our feet on the ground. I have a lot of desire, I can give a lot and I want to pass this on to my teammates."